Achieving Optimal Specialty Cerebrospinal Fluid (CSF) Testing: Are Electronic Medical Record Order Sets Helpful?

BACKGROUND: Specialty PCR testing has become available for lumbar puncture to determine the cause of infectious meningitis and encephalitis. Testing with low pre-test probability may increase antimicrobial therapy while results are pending and create increased direct costs. We aim to describe the appropriateness of testing before and after the implementation of electronic medical record (EMR) order sets designed to reduce excessive testing of CSF by creating two lists of tests: (1) a routine panel for all patients and (2) a list of optional specialty tests designed to be utilized after the nucleated cells are resulted. METHODS: Retrospective study of adult patients undergoing lumbar puncture with suspicion for CNS infection pre-and post-implementation of EMR order sets from January 2016–March 2017. Consecutive patients with complete charts were reviewed from a tertiary care center. Data collected included demographics, co-morbid conditions, clinical presentation, and lumbar puncture results. The primary outcome of interest was the frequency of CSF specialty testing in patients with ≤ 10 nucleated cells/µL in the CSF. RESULTS: Two hundred patients had ≤ 10 nucleated cells/µL in the CSF (n = 108 in pre-EMR group; n = 92 in post-EMR group). Of these patients 74% and 48.9% had Herpes Simplex Virus (HSV) PCR testing done pre and post EMR changes (P < 0.05). Enterovirus PCR testing remained similar among both groups (37% pre-EMR order sets vs. 36.9% post-EMR order sets, P = 0.99). Lyme PCR testing decreased between pre- and post-groups (26.8% vs. 9.7%, P < 0.05). CSF Epstein-Barr virus PCR testing also dropped significantly from 26.9% to 7.6% (P < 0.05). All specialty PCR testing that was performed on patients with ≤ 10 nucleated cells/µL in the CSF were negative. Paradoxically, HSV antibody testing increased post-implementation of EMR order sets (21.7% vs. 0%, P <0.05). Total costs of tests on average decreased by $70.71 per patient post EMR changes. CONCLUSION: In this cohort, CSF specialty testing was common but decreased after EMR changes. Laboratory stewardship can be improved with EMR changes but further education is needed to prevent unnecessary tests. Unwanted tests (HSV antibodies) may be increased as prescribers are unable to locate familiar tests. DISCLOSURES: M. D. Nailor, Astellas: Scientific Advisor and Speaker’s Bureau, Consulting fee and Speaker honorarium. Merck: Grant Investigator, Research grant.